Furnace



FURNACE Filed July 19. 1923 3 Sheets-Sheet 1 a I l I I I I I I I I I l II I l l l l l I I w\W///K\ Wm\\% Filed July 19. 1923 3 Sheets-Sheet. 2

l I l I I l l l l l l l l i July 1 1924. v 1.499.532

c. J. HUBER FURNACE Filed July 19 .1923 3 Sheets-She L 3 Patented July1, 1924.

UNITED STATES I 1,499,532 PATENT OFFICE.

CHARLES J. HUBER, 0F BALTIMORE, MARYLAND.

FURNACE.

To all whom it may concern:

Be it known that I, Cr ARLEs J. HUBER, a citizen of the United States ofAmerica, residing in the city of Baltimore, State of Maryland, haveinvented certain new and useful Improvements in Furnaces, of which thefollowing is a specification.

In the present existing furnace practice in which coal is fed directlyto the top of the fire, being either spread over the grate surface bymeans of a shovel, or carried to and through the combustion area by somemore elaborate stoking apparatus, great difliculty is encountered inobtaining complete combustion.

Ordinarily there is a very considerable loss of fuel in the form ofsmoke and gas, which being formed or generated well forward or towardthe center of the furnace, does not become sufiiciently mixed with airin its passage from this point to the bridge wall to form a combustiblemixture and therefore it escapes and passes up the chimney without beingconsumed. Failure to achieve complete combustion with consequentdischarge of gas and smoke not only results in the loss of a largenumber of heat units otherwise obtainable from the coal, but also in thecreation of a nuisance to those located in the vicinity of the furnaceon account of the unpleasant and harmful effect of the gases and smokeon human beings as well as furniture, buildings, clothes, etc.

The object of the present invention is to achieve increased economy byproviding for complete combustion of the coal eliminating smoke andunconsumed gases by complete combustion thereof. The result thusoutlined is obtained by coking the coal at the front of the furnaceafter it enters the furnace but before it is fed to the fire, the vaporsfrom the coal being thus generated or driven off from the coal at thefront of the furnace are mixed with air and burned completely beforethey reach the bridge wall, with the result that not only are the heatvalues of these vapors consisting of combustible gases and smoke madeavailable, but the harmful effects of mixing these gases and smoke withthe outside air are avoided.

In the form of the invention shown, cok ing of the coal is accomplishedby means of a coking shelf of refractory material, as fire brick at thefront of the furnace above the fire together with a reflecting and heatApplication filed July 19,

storing member of refractory material above the shelf, and means foradmittin air at the front of the furnace beneath the shelf and forwardof the coal dropped from the shelf so as not to be choked by the fuel,and so the smoke and gases released in the coking of the coal aremingled with air and burned as they pass over the fire toward the bridgewall. In other words, all the volatile elements are driven off from thecoal at the front of the furnace and mingled with air freely admitted infront of the coal on the grate and burned before they reach the bridgewall. Every provision is made for subjecting the coal on the cokingshelf to the most intense heat so as to coke each charge completelybefore it is fed to the fire, thus releasing the distillable portionsand burning them completely by mixing with air at the high furnacetemperatures, obtaining the greatest possible amount of heat from thefuel and preventing smoke.

The invention has been developed in connection with a furnace having anordinary hopper feed. The hopper feed includes a pusher, the operationof which first places a charge of coal on the shelf to be coked and thenwhen it has been coked, pushes it from the shelf so that it dropsontothe grate after all the volatile matter has been driven oil.

The pusher may be timed and operated in any suitable manner as by poweror by hand. In the fo'rm shown, it is intended to be manually actuatedand timed.

In the accompanying drawing,Ihave illustrated a furnace embodying thecoking and smoke-consuming feature of my invention.

In the drawing:

Figure l is a vertical, central, longitudinal section of a furnaceconstructed and equipped in accordance with my invention.

Figure 2 is an elevation looking at the outside of the furnace from thefront.

Figure 3 is a transverse section taken on the line 33 of Figure 1 andlooking at the front of the furnace, coking shelf,'etc., from inside thefurnace. The observer is looking in the direction of the arrow in Figure1.

Figure 4 is a section corresponding to Figure 1 in thatit is taken inthe same vertical, longitudinal plane, showing the coking shelf, thebridge wall and the hopper, the pusher being in advanced position.

Figure 5 1s a similar view, the pusher be ing partly retracted;

Referring to the drawing bynumerals, the furnace'is in the main of theusual'con struction having a bridge wall, 1, an arch, 2, ash pit, 3,grate, 4, and feed hopper, 5. The feed hopper is closed at the bottom bya sliding pusher or feed piston, 6. This,

as shown, is of L-shaped cross section providing for the entrance of.the outside air into a chamber, 7, beneath the L, serving to cofolthecoal in the hopper. The pusher is actuated by a link, 8, pivotallyconnected thereto and in turn pivotallyconnected to a lever, arm, 9,which is rigidly secured to an actuating arm, 10, said arm, 10, andlink, 9, combined having a bell crank lever action, both being pivotedat their meeting point or vertex on a stationary journal pin, 11.

The pistonor usher, 6, slides on a horizon talplate, 12, ,mown as thefeed plateand extending across the furnace from side to side and beingrigidly mounted in the furnac e structure, it being understood that thefurnace may be of any desired width, hav ing; a corresponding numberofhoppers and p ushers depending on the number of boilers which may beset side by side in a battery thus equipped. 1

,An important feature of the invention resides in the construction andarrangement of .tl1e parts in the vicinity of the hopper feed opening,14, and the co-operation therewith of the feeding member or pusher, 6.The coking shelf, 15, is placed with its top surface; in thehorizontalplane of the top surface ;of.the feed plate, 12, and projects into thefurnace. from the feed opening. This shelf is formed of resistivematerial tongued' and grooved for mutual engagement, of the lateraledges as shown at 17, 18 in Figure-3, the tongues being indicated by.reference character, 17, and the grooves by reference character 18. Thefire bricks forming the coking shelf are also shown as provided withlongitudinal T slots, 19, dotted in cross section in Figure 3, the slotsextending downwardly from the top sur- 7 faces of thebricks, the T beinginverted and the portion ofthe slot corresponding to the cross arm beingnear or below the center and extending longitudinally thereof,cooperating with these T slots and occupying the same, I haveshown Tbars, 20, secured to andiprojecting' from the feed plate, 12,

directly backward into the furnace. The

shelf is preferably builtupthe fire bricks thus formed by placing the Tslots in engagement with the T irons and sliding the bricks backwardagainst the feed plate, 12,

the T irons entering the slots, and the 7.

of the cross bar, 12, and the latter is pro vided with a depending web,22, against which the ends of the bricks abut, whereby they are furtherpositioned and supported and. aligned. i

The top wall of the hopper opening, 14, is formed by a dependingportion, 24, of the arch 2. This depending member, 24, is composed ofblocks of resistive material placed side by side, and extending acrossthe front of the furnace. They are partially supported by ears, 30,entering apertures, 31, in the blocks. This portion; of the arch isshown as formed as to its lower innerv surface in a full, substantiallycircular curve, 25, which *gives the opening an increasingcross-sectional area from the entrance 26, .thereof inwardly. Beyond thedepending portion, 24, of the arch, the rear portion, 27, thereof iscurved and constructed in the usual manner. This formation of thedepending portion of the arch, in cooperation with the flat shelf, 15,contributes to the coking action by permitting the deposit of the coalon the shelf,as illustrated, where it is permitted to become coked, theformation of the opening, i. e., its increasing taper inward bycontributing to the prevention of cramping when the coke thus formed isagain engaged by the pusher being broken up thereby and pushed fromtheshelf so that it drops on the front of the grate. The depending portion24 is directly exposed to radiation from the hot test part of thefireand so becomes highly heated. The heat thus stored in this member 24has a very important effect in heating the green or cold fuel whichcomes direct-ly in contact with it as it enters the furnace,the heatingeffect being produced both by conduction, i. e., direct contact, and byreflection and'radiatio'n. The shelf which is also of heavy fire brickor other'suitable resistive material, is alsoa very eflicient heatreservoir, receiving the radiation directly from the fire andtransferring the heat to thefuel, and on account of the narrowness ofthe shelf, some of the fuel is also-exposed directly to radiation fromthe fire.

-Beneath the shelf, 15, adjacentthe front' of the grate and justforward'of the fire, I have shown a grid, 35, the openings in which leadfrom the ash pit to the fire box. These openings which are well forwardof the rear edge, 36, of the shelf, 15, provide fora-the admission ofair at a pointand in a manner'which permits it to combine in combustibleproportions with the smoke and gases resulting from the coking of the.

- is almost completely out off when and where it is most needed. As'theraw coal gives off practically all the gas and smoke generated in thefurnace, it will be apparent that, under the conditions described, thedischarge of smoke and unconsumed gases from the chimney can hardly beprevented for the air which is admitted to the fire box enters well backin the furnace and it is not suflicient in quantity and there is notsufficient opportunity for it to become heated and mixed with smoke andgas generated at the front of the furnace, while these products ofpartial combustion are in the heated zone to provide for their furtherand complete combustion.

In accordance with the present invention, the coal is coked before it isfed to the grate. In coking it becomes caked into a solid mass and whenbroken up by the pusher, the fragments are so large that the air passesbetween them. Also I have provided an extra air passage beneath thecoking shelf. This passage it will be noted is placed well forward ofthe edge of the coking shelf so as to be free of the fuel which isdropped from the shelf so that it is not choked in the normal operationof the grate providing for a free passage of the air from the ash pit tothe fire box which is not true of the grate area proper. In this way,suflicient air is admitted at the front of the furnace to provide forcomplete combustion of the smoke and gases generated in coking, and thegases are generated at the extreme forward end of the furnace in aposition which provides a long path for the gases from the point ofgeneration to the flue. In making this passage, they become completelymixed with air admitted to the front of the fur nace, as aforesaid, theair has suflicient chance to become heated, and mixing takes placewithin the heated area providing for complete combustion and theelimination of smoke and raw, poisonous gases, and also for thegeneration of a correspondingly increased amount of heat in a positionin which it .will be available for heating the boiler.

The manner of operating the coking apparatus illustrated will be easilyunderstood. The hopper is filled with coal, usually bituminous, a largepart of it being so finexthat it would tend to drop through the grate.The pusher is withdrawn as by raising the handle, 37, fitted onto thelevel arm, 10. On withdrawal of the pusher, a. charge of'fuel settlesdown from the open bottom of the hopper onto the feed plate, 12, infront of the pusher. The lever or handle, 3 i then lowered, advancingthe pusher and moving it forward onto the coking shelf within thefurnace, where it is subject by radiation and convexion, to the fulltemperature of the furnace and to conduction and radiation from thehighly heated depending member 24 and from the coking shelf 15, both ofwhich are of heavy ceramic material adapted to receive and store andradiate heat to the very best advantage. The pusher is then withdrawn,permitting a new charge to pass downward from the hopper to a positionin front of the pusher, and the parts are allowed to remain in thisposition until coking is complete and the furnace is ready to receive anew supply of fuel. The pusher is then advanced, forcing the new chargeforward through the feed opening, 14, onto the shelf, and by thepressure thus applied breaking up the coke on the shelf, causing it tofall on the forward portion of the grate, as illustrated. Coking andfeeding may thus tend to follow immediately after each stok ingoperation, it being apparent that stoking and feeding may beaccomplished in any suitable manner, either by hand or by power, thecoking and smoke consuming device illustrated being capable of use withany type of feeding and stoking apparatus.

I have thus described specifically and in detail a furnace structureembodying my invention in the preferred form, together with theoperation of the same in order that my invention may be fully understoodby those skilled in the art, however, the specific terms herein are useddescriptively rather than in a limiting sense, the scope of theinvention being defined in the claims.

What I claim and desire to secure to Letters Patent is:

1. In a furnace having a grate, a flue, a bridge wall and a feedopening, a coking shelf extending backward into the furnace at the lowerside of the feed opening in front of the furnace and above the grate,the feed opening having a top wall at the front of the furnace andexposed to radiation from the fire and extending backward above theshelf and having an upward inclination towards the rear, the cokingshelf and the top wall being of heavy ceramic material and serving asheat reservoirs to receive and store heat and transmit it to the fuel,and a free and unobstructed air passage beneath the shelf.

2. Ina furnace having a the box, a grate, a flue, and a feed opening atthe front of the furnace. above the grate, a coking shelf extendingbackward into the furnace near the bottom of the feed opening, saidshelf being composed of resistive, ceramic inate'rial, a heat retainingand transmitting member immediately over the shelf, thesame beingexposed to the direct radiation" from the fire and being in contact withthe fuel on the shelf, and an air opening leading from the ash pit intothe fire box beneath the coking shelf and spaced for- Wardly from therear edge thereof.

3. In a furnace having a grate, a feed opening, a coking shelf spacedabove ther e t the f on f: the f n h opening having a top Wall extendingback Ward above the shelf, both the top Wall and the, coking shelfbeing, directly exposed to radiation from the fire and of heavy ceramicmaterial, constituting means for storing heat and transmitting it to thefuel, and. an air opening spaced beneath the coking shelf and forward ofthe rear edge thereof.

Signed by me; at Baltimore, Maryland, this 17th day of July, 1923.

CHARLES J. Witnesses: PORTER H. ELAUTT, ELIZABETH KEECH.

